Fix dependency (#18)

We recently received the following error in the lambbda
cloudwatch logs..

```
Runtime.ImportModuleError: Unable to import module 'app':
cannot import name 'DEFAULT_CIPHERS' from 'urllib3.util.ssl_'
```

This seems like a library conflict between botocore and urllib3
so we update according to workaround proposed at these locations:

* https://stackoverflow.com/questions/76414514/cannot-import-name-default-ciphers-from-urllib3-util-ssl-on-aws-lambda-us
* boto/botocore#2926
* psf/requests#6432

Pipfile

@@ -15,7 +15,7 @@ coverage = "~=7.0"
 
 [packages]
 crhelper = "~=2.0"
-synapseclient = "~=2.6"
+urllib3 = "<2"
 
 [requires]
 python_version = "3.9"